First answer to you question like you are able to See the session Since Might be at that time the session Will be in the Marked as kill. after then the Pmon is responsible for clearing all the Processes.But mean while the time that is taken by PMON to clear the killed session's or Processes I mean here Will stay at that Instant of time.So to kill the session Immediate Please use the following syntax.

i had also try to killed those killed session using immediate and record still get from v$session. and already 30 mins over but killed sessions still show in v$session. 30 minutes is not enough for clear it?

@Roachcoach, i understand after marked kill, then alter system kill session do nothing. But my main concern is in v$session it show killed for a longer time, how to kill those killed session. One way is os kill using kill -9 spid, but when i try to find out spid, i failed. I try to join with v$process for spid, but no row return for those killed session.

I also try to find out active transaction using v$transaction view, but v$transaction has no record.

@Roachcoach, i understand after marked kill, then alter system kill session do nothing. But my main concern is in v$session it show killed for a longer time, how to kill those killed session. One way is os kill using kill -9 spid, but when i try to find out spid, i failed. I try to join with v$process for spid, but no row return for those killed session.

I also try to find out active transaction using v$transaction view, but v$transaction has no record.

As has been said, the sessions are killed (so no other alter system on them will work) and the processes have also been killed (or disappeared), so there is nothing more than to wait (or restart the instance).

You can use only ONE of these statements on a session.
You have to choose how you want to terminate it.
Carefully read the documentation about the different options so you can know what is the best one for the case you are (now for this specific case it is too late).

i had also try to killed those killed session using immediate and record still get from v$session. and already 30 mins over but killed sessions still show in v$session. 30 minutes is not enough for clear it?

Sure, there are cases you have to use "disconnect session" instead of "kill session", yuo have to analyze the situation to know which command to execute.
Disconnect has in the end the effect to kill the Oracle server process but this is Oracle that does it and so it knows what to do before to have a clean state.
Killing at OS level is a behaviour of last century when "disconnect session" didn't exist.
And "disconnect session" was introduced to address the "kill session" issue.